I've been shopping around on Amazon.com and Walmart.com to find a portable air compressor to handle airing up the tires in my pickup and 5th wheel. I think the tires on both my PU and 5th wheel are designed to hold around 80psi, so I'd need something that can handle more than just a standard card or light pickup. Most of the little hand-held compressors are in the $50-$70 range and all of them seem to plugin to cigarette lighters. Ideally I'm looking for something that has a standard wall plugin as I don't think be able to reach the 5th wheel tires when I am plugged into the cigarette lighter. Curious if anyone has found something small and reliable. I'm pushing weight limits on my rig, so I'm trying to find something small and lightweight.

It fits quite handily in my forward bay and at 115 psi is adequate for my 80 psi requirements. I have two coiled air hoses at 25' each and can reach any of my tires and the air hitch without taking the unit out of the bay. I keep the tanks filled when traveling and can top up a slow leak or make adjustments to the TrailAir pin box, if necessary, without needing 120v and I can then limp (if a tire) to a repair facility or get off the road. It makes it very convenient to air down the truck's rear tires for ride comfort when sightseeing and then filling back up before hitching for getting back on the road. I even use it for winterizing. I ran a 120v plug into the front bay so that I don't need to plug it in to an extension cord; if the 5er has power, so does the compressor.

Pros:
Lightweight - 45 lbs
Quiet (Quietest compressor I own and I've got a bunch around the farm)
Upright design - fits easily in my front bay
Twin tank - holds a fair amount of air for emergency use

Cons:
Only 115 psi - if you have a MH or need much more than 80 psi it is borderline or not applicable at all.
Only 4.6 gallon tanks - won't hold enough air to air up a flat, but, will top off a slow leak or adjust an air ride pin box.
Not cheap - well worth the price to me, though.

Well if your looking for something inexpensive yet has a high pressure but low volume look at a slime. I carry one with me. It takes a while but low and behold it gets the job done. It might take 5 minutes to pump up 5 pounds but if your not in a hurry. Small and compact.
they also make a assortment of other 12v compressors

I've got a "nearly" identical (different nameplate) compressor as the one Webslave linked to. It's a pretty good unit, and I must have gotten a sweet deal on it; I paid about $130 at my local Costco. I've had it 3+ years without a complaint.

RoyB has a nifty one he uses; I'm suprised he hasn't commented on this thread yet!